Ceramic heaters have been used to date for various applications, including an ignition heater of an oil fan heater and a glow plug for use in assistance to the starting of diesel engine operation. For example, such a ceramic heater is constructed by embedding a heat-generator made of electrically conductive ceramics in a base body made of insulating ceramics. In constructing the ceramic heater, as a material used to form the heat-generator, there has been known a substance composed predominantly of at least one of a suicide of molybdenum, tungsten, or the like, a nitride thereof, and a carbide thereof. Moreover, as a material used to form the base body, there has been known a substance composed predominantly of silicon nitride.
However, in general, the material which forms the heat-generator is greater in thermal expansion coefficient than the material which forms the base body. Accordingly, there is a possibility that cracks appear in the base body due to a thermal stress arising between the two materials at a time of heat generation. In view of this, there has been proposed a technique that a rare-earth component, a silicide of chromium, and an aluminum component are contained in the base body, in order to reduce the difference in thermal expansion coefficient between the two materials (refer to Patent Literature 1, for example).